Histiocytosis X cells in eosinophilic granuloma express Ia and T6 antigens.

Morphologic similarities between histiocytosis X (HX) cells and epidermal Langerhans cells (LC) have led to the hypothesis that HX represents a proliferative disorder of LC. In order to prove the validity of this assumption, we tested single cell suspensions isolated from an eosinophilic granuloma type HX lesion for the presence of various antigenic determinants defined by monoclonal antibodies using an immunoelectron microscopic technique. An anti-Ia reagent reacted with essentially all histiocytic cells and a small portion of lymphocytes whereas plasma cells and eosinophils were negative. T6 antigen, in contrast, was disclosed exclusively on HX cells either with or without Birbeck granules. Pan-T cell-reagent OKT3 reacted only with small lymphocytes. The finding that HX cells from eosinophilic granuloma lesions are the only cells that have the identical surface marker equipment as epidermal LC (Ia antigens, T6 antigen, Fc-IgG, and C3 receptors) strongly supports the concept that these cells are derived from the LC lineage.

Circulating immune complexes in acute schistosomiasis.

The sera of patients with acute and chronic schistosomasis were tested for the presence of circulating immune complexes with the 125I-Clq binding assay. Fourteen out of fifteen (93%) patients with acute schistosomiasis had elevated 125I-Clq binding activity, while only two out of eleven (18%) patients with chronic disease had C1q binding complexes. This difference was significant (P less than 0.001) and paralleled the degree of clinical didsease activity between the two groups of patients. IgG and IgM were readily detected in all of these circulating complexes but the specific parasite antigens initiating their formation could not be defined. The level of circulating immune complexes was inversely correlated with the absolute eosinophil counts for individuals in the acutely infected group, an observation compatible wiht the hypothesis that a functional role for the eosinophil is the destruction and elimination of immune complexes.

Autoimmune vitiligo: detection of antibodies to melanin-producing cells.

Vitiligo, a disorder characterized by the destruction of melanocytes, is often associated with diseases in which there are increased frequencies of autoantibodies. For this reason we investigated two patients with vitiligo, alopecia universalis, mucocutaneous candidiasis, and multiple endocrine insufficiencies for antibodies to melanin-producing cells. Using direct immunofluorescence of normal and vitiliginous skin from both patients and indirect immunofluorescence with both patients' serum, we could not detect these antibodies. However, an immunofluorescent complement-fixation test demonstrated a circulating antibody that bound to melanocytes in human skin, nevus cells and melanoma cells. Specificity of cellular fluorescence for nevus and melanoma cells was shown on serial sections stained with hematoxylin and eosin and was inferred for melanocytes from their distribution in human skin and their presence when the normal but not vitiliginous skin of both patients was used as substrate. This antibody was characterized as an IgG that activated complement via the classical pathway.

Immunofluorescent localization of basement membrane in lesions of dermatitis herpetiformis.

Dermatitis herpetiformis (DH) is a blistering disease with a characteristic histology that includes papillary edema, neutrophilic papillary microabscesses, and development of subepidermal blisters. In spite of this pathologic sequence occurring entirely beneath the basement membrane zone, prior studies have indicated that the basement membrane, as defined by period acid-Schiff (PAS) or silver stains, lies at the floor of fully formed blisters or is destroyed by the disease process. To more accurately assess its location in primary lesions of DH, the basement membrane was stained using immunofluorescent techniques. Lesional skin from 5 patients with DH was used as substrate for indirect immunofluorescence with sera from patients with bullous pemphigoid (BP) and fluoresceinated antihuman IgG. The BP-stained basement membrane was attached to the roofs of early blisters, where it would be expected from the pathologic sequence of blister formation. PAS stains of the same or serial sections show the basement membrane to be in the roof or at the floor of the blisters. PAS stains of sections from formalin-fixed lesional skin, on the other hand, show the basement membrane to routinely lie at the blister floor, when not destroyed. The BP-stained epidermal basement membrane has greater anatomic and functional significance than either the PAS-or silver-stained basement membrane for two reasons: (1) it corresponds to a specific morphologic structure, the lamina lucida, a part of the epidermis, and remains attached to the rest of the epidermis unless destroyed; and (2) it is antigenic, capable of binding with BP antibodies.

Effect of sulfones on complement deposition in dermatitis herpetiformis and on complement-mediated guinea-pig reactions.

The role of complement and the mechanism of sulfone action in dermatitis herpetiformis (DH) have not yet been established; prior studies have presented conflicting data regarding the effect of sulfones on complement activation and deposition. Thirty-eight DH patients were studied. Twenty-four of 25 perilesional skin biopsies and 50 of 67 normal-appearing skin biopsies showed the third component of complement (C3) deposited in areas corresponding to those of IgA deposition. Nine of 10 patients with bound C3 in normal-appearing and perilesional skin during periods of active disease continued to have C3 in normal-appearing skin when treatment with sulfones kept them completely free of lesions for 2 to 8 weeks. When either Hartley-strain or C4-deficient guinea pigs were given up to 150 mg/kg sulfoxone (a water-soluble sulfone) intraperitoneally for 8 days before elicitation of active Arthus, reverse passive Arthrus reactions, or Forssman shock, there was no difference in time course, character, or intensity of reactions when compared to saline-treated control animals. We were therefore unable to demonstrate any effect of sulfones on complement deposition in DH skin or on complement activation in classical or alternate complement pathway-mediated guinea-pig reactions.